Machine Type Communication (MTC) is being discussed in various wireless communication standards bodies as a new trend of wireless technology of communication network applications which typically do not require human interaction.
A broad definition of MTC is an automated communication network to and from machines. One major category of MTC devices are expected to have the characteristics of very low power consumption, very small data transmissions and a very large number of terminals. An example MTC application that fits within this category may for example be energy consumption monitoring of home appliances for smart grid systems.
Uplink-only relaying is a network topology which may be used to address the issue of transmit power limitation in low-cost Machine Type Communication (MTC) devices when deployed, for instance, in macro cellular Long-Term-Evolution (LTE) networks. In general there is sufficient system gain on the downlink (base station to terminal device) to support MTC devices (or User Equipment UE) (MTC-UE) at the cell edge of the macrocell of the eNodeB (eNB) but with the low output power of the MTC devices the uplink (terminal device to base station) system gain is significantly reduced compared with the downlink. The use of a single hop uplink-only relay node (MTC-RN) can be used to address this issue and close the link budget for MTC-UE. A single hop may be assumed provided that the MTC-RN can be expected to have similar characteristics to an LTE UE. In a network where relay nodes (also referred to herein as relay devices) are utilised to relay uplink data from the terminal devices to the eNodeB, the eNodeB may be referred to as a donor eNodeB (DeNB).
An uplink only single-hop relay is described in US2008/0285499.